The present invention relates to the construction field. It relates in particular to the treatment of structures made from a cement-based product and having steel rebars, allowing rebar corrosion to be inhibited, preventing the alkali reaction and avoiding the presence of alkalis and sulfates in the structure.
Steel rebars in structures made from concrete are subject to corrosion. The concrete itself may undergo degradation by spalling due to swelling as a result of alkali reactions and to the presence of sulfates or alkalis. This spalling generates cracks that allow water to penetrate into the structure and thus promotes rebar corrosion. This phenomenon is perpetuated until the concrete has been completely destroyed.
Rebar corrosion is promoted by contaminating elements, such as chlorides present in particular in the original sea sand used, owing to the scarcity of river sand, or provided by the salts used for deicing roadways. These contaminants may also be found in sullied demolition-recycling or quarry aggregates, or in products used lately as concrete admixtures (chlorides or sulfates).
The carbonation of concrete reduces the pH of concrete structures. The rebars, surrounded by concrete, are then no longer protected by its high pH and become sensitive to corrosion. Concrete cracking due to the reactions described above promotes the penetration of water into the structure and consequently corrosion of the rebars.